Mould for producing atomizer nozzles, mould set, negative mould and method for producing an atomizer nozzle

Abstract

A mold for producing atomizer nozzles, wherein a mouthpiece core mold part defines an inner wall of the mouthpiece, at least in the region of a transition between the mouthpiece and the flow chamber, and is of integral design, wherein the flow chamber core mold part has a substantially smooth surface and continuous contours in the region of the transition from the flow chamber to the mouthpiece, and wherein the mouthpiece core mold part is placed against the flow chamber core mold part at the transition between the flow chamber and the mouthpiece.

Claims

1. A mould for producing an atomizer nozzle with a flow chamber defined by a flow chamber inner wall and a mouthpiece chamber defined by a mouthpiece chamber inner wall, the mouthpiece chamber adjoining the flow chamber and having a narrower cross section than the flow chamber for the emergence of liquid to be atomized, the mould having multiple parts and a cavity, the cavity corresponding in negative form to outside and inside dimensions of the atomizer nozzle and being filled with liquid or thixotropic production material thereafter made to solidify, the mould having a flow chamber core mould part defining the flow chamber inner wall and a mouthpiece core mould part defining the mouthpiece chamber inner wall at least in a region of a transition between the mouthpiece chamber and the flow chamber, the flow chamber core mould part having an outer surface with a substantially smooth and continuous contour in the region of the transition between the flow chamber and the mouthpiece chamber, the outer surface defining the flow chamber inner wall, the mouthpiece core mould part having an edge encircling the outer surface of the flow chamber core mould part and being disposed in sealing contact against the substantially smooth and continuous contour of the outer surface of the flow chamber core mould part at the transition between the flow chamber and the mouthpiece chamber, the mouthpiece core mould part having a configuration which tapers in a direction towards the edge of the mouthpiece core mould part.

2. The mould according to claim 1, wherein the mouthpiece core mould part defines the mouthpiece chamber inner wall from the region of the transition between the mouthpiece chamber and the flow chamber to an outlet edge of the mouthpiece chamber from which liquid emerges.

3. The mould according to claim 1, wherein the edge of the mouthpiece core mould part forms an intersection of an outer surface of the mouthpiece core mould part and a bearing surface of the mouthpiece core mould part facing away from the outer surface of the mouthpiece core mould part, the outer surface of the mouthpiece core mould part defining the mouthpiece chamber inner wall and the bearing surface is substantially parallel with the substantially smooth and continuous contour of the outer surface of the flow chamber core mould part in the region of the transition between the mouthpiece chamber and the flow chamber.

4. The mould according to claim 1, wherein the substantially smooth and continuous contour of the outer surface of the flow chamber core mould part disposed in sealing contact with the edge of the mouthpiece core mould part is exposed to contact liquid or thixotropic production material located within the cavity of the mould.

5. The mould according to claim 4, wherein the sealing contact between the edge of the mouthpiece core mould part and the outer surface of the flow chamber core mould part defines a parting line between the mouthpiece core mould part and the flow chamber core mould part, the mouthpiece core mould part defines a central axis corresponding to a direction along which liquid emerges from the mouthpiece chamber, the edge is a radially outermost part of the mouthpiece core mould part at the parting line and the substantially smooth and continuous contour is a radially outermost part of the outer surface of the flow chamber core mould part at the parting line.

6. The mould according to claim 5, wherein the substantially smooth and continuous contour of the outer surface of the flow chamber core mould part extends beyond the parting line.

7. A mould for producing an atomizer nozzle with a flow chamber defined by a flow chamber inner wall and a mouthpiece chamber defined by a mouthpiece chamber inner wall, the mouthpiece chamber adjoining the flow chamber and having a narrower cross section than the flow chamber for the emergence of liquid to be atomized, the mould having multiple parts and a cavity, the cavity corresponding in negative form to outside and inside dimensions of the atomizer nozzle and being filled with liquid or thixotropic production material thereafter made to solidify, the mould having a flow chamber core mould part defining the flow chamber inner wall and a mouthpiece core mould part defining the mouthpiece chamber inner wall at least in a region of a transition between the mouthpiece chamber and the flow chamber, the flow chamber core mould part having an outer surface with a substantially smooth and continuous contour in the region of the transition between the flow chamber and the mouthpiece chamber, the outer surface defining the flow chamber inner wall, the mouthpiece core mould part having an edge encircling the outer surface of the flow chamber core mould part and being disposed in sealing contact against the substantially smooth and continuous contour of the outer surface of the flow chamber core mould part at the transition between the flow chamber and the mouthpiece chamber, the outer surface of the flow chamber core mould part being frustoconical or conical in the region of the transition between the flow chamber and the mouthpiece chamber.

8. The mould according to claim 7, wherein the edge of the mouthpiece core mould part presses into the outer surface of the flow chamber core mould part to achieve the sealing contact.

9. The mould according to claim 7, wherein the mouthpiece core mould part has a frustoconical bearing surface disposed in opposed and contacting relation with the frustoconical or conical outer surface of the flow chamber core mould part.

10. The mould according to claim 7, wherein the flow chamber core mould part and the mouthpiece core mould part are provided with a projection and with a recess matching the projection, the projection engaging within the recess when the mouthpiece core mould part is disposed against the flow chamber core mould part.

11. A mould for producing an atomizer nozzle with a flow chamber defined by a flow chamber inner wall and a mouthpiece chamber defined by a mouthpiece chamber inner wall, the mouthpiece chamber adjoining the flow chamber and having a narrower cross section than the flow chamber for the emergence of liquid to be atomized, the mould having multiple parts and a cavity, the cavity corresponding in negative form to outside and inside dimensions of the atomizer nozzle and being filled with liquid or thixotropic production material thereafter made to solidify, the mould having a flow chamber core mould part defining the flow chamber inner wall and a mouthpiece core mould part defining the mouthpiece chamber inner wall at least in a region of a transition between the mouthpiece chamber and the flow chamber, the flow chamber core mould part having an outer surface with a substantially smooth and continuous contour in the region of the transition between the flow chamber and the mouthpiece chamber, the outer surface defining the flow chamber inner wall, the mouthpiece core mould part having an edge encircling the outer surface of the flow chamber core mould part and being disposed in sealing contact against the substantially smooth and continuous contour of the outer surface of the flow chamber core mould part at the transition between the flow chamber and the mouthpiece chamber, the mouthpiece core mould part being a first mouthpiece core mould part, the mould further including a second mouthpiece core mould part having a different diameter than a diameter of the first mouthpiece core mould part in the region of the sealing contact between the flow chamber core mould part and the first mouthpiece core mould part.

12. A method for producing an atomizer nozzle with a mould having a flow chamber defined by a flow chamber inner wall and a mouthpiece chamber defined by a mouthpiece chamber inner wall, the mouthpiece chamber adjoining the flow chamber and having a narrower cross section than the flow chamber for the emergence of liquid to be atomized, the mould having multiple parts and a cavity, the cavity corresponding in negative form to outside and inside dimensions of the atomizer nozzle and being filled with liquid or thixotropic production material thereafter made to solidify, the mould having a flow chamber core mould part defining the flow chamber inner wall and a mouthpiece core mould part defining the mouthpiece chamber inner wall at least in a region of a transition between the mouthpiece chamber and the flow chamber, the flow chamber core mould part having an outer surface with a substantially smooth and continuous contour in the region of the transition between the flow chamber and the mouthpiece chamber, the outer surface defining the flow chamber inner wall, the mouthpiece core mould part having an edge encircling the outer surface of the flow chamber core mould part and being disposed in sealing contact against the substantially smooth and continuous contour of the outer surface of the flow chamber core mould part at the transition between the flow chamber and the mouthpiece chamber, the edge of the mouthpiece core mould part forming an intersection of an outer surface of the mouthpiece core mould part and an inner bearing surface of the mouthpiece core mould part facing away from the outer surface thereof, the outer surface of the mouthpiece core mould part defining the mouthpiece chamber inner wall from the intersection to an outlet edge of the mouthpiece chamber from which liquid emerges, and the outer and inner surfaces of the mouthpiece core mould part together defining an angle of less than 90 degrees at the edge, the method including applying a preload between the mouthpiece core mould part and the flow chamber core mould part, maintaining the preload during filling of the mould with liquid or thixotropic production material, and slightly pressing the edge of the mouthpiece core mould part into the material of the flow chamber core mould part at the transition between the flow chamber and the mouthpiece chamber and deforming the flow chamber core mould part at the transition.

13. A mould for producing an atomizer nozzle with a flow chamber defined by a flow chamber inner wall and a mouthpiece chamber defined by a mouthpiece chamber inner wall, the mouthpiece chamber adjoining the flow chamber and having a narrower cross section than the flow chamber for the emergence of liquid to be atomized, the mould having multiple parts and a cavity, the cavity corresponding in negative form to outside and inside dimensions of the atomizer nozzle and being filled with liquid or thixotropic production material thereafter made to solidify, the mould having a flow chamber core mould part defining the flow chamber inner wall and a mouthpiece core mould part defining the mouthpiece chamber inner wall at least in a region of a transition between the mouthpiece chamber and the flow chamber, the flow chamber core mould part having an outer surface with a substantially smooth and continuous contour in the region of the transition between the flow chamber and the mouthpiece chamber, the outer surface defining the flow chamber inner wall, the mouthpiece core mould part having an edge encircling the outer surface of the flow chamber core mould part and being disposed in sealing contact against the substantially smooth and continuous contour of the outer surface of the flow chamber core mould part at the transition between the flow chamber and the mouthpiece chamber, the mouthpiece core mould part having an outer surface defining the mouthpiece chamber inner wall of the mouthpiece chamber and an inner surface facing away from the outer surface of the mouthpiece core mould part, the inner surface being oriented transversely relative to the outer surface of the mouthpiece core mould part and defining a recess in the mouthpiece core mould part which opens toward the flow chamber core mould part, the flow chamber core mould part having an end portion extending into the recess beyond the edge of the mouthpiece core mould part, the edge of the mouthpiece core mould part defining an intersection of the outer and inner surfaces of the mouthpiece core mould part, the outer surface of the flow chamber core mould part being a first outer surface and the flow chamber core mould part including a second outer surface defining an exterior surface of the end portion of the flow chamber core mould part, the exterior surface being disposed in facing relation with the inner surface of the mouthpiece core mould part.

14. A mould for producing an atomizer nozzle with a flow chamber defined by a flow chamber inner wall and a mouthpiece chamber defined by a mouthpiece chamber inner wall, the mouthpiece chamber adjoining the flow chamber and having a narrower cross section than the flow chamber for the emergence of liquid to be atomized, the mould having multiple parts and a cavity, the cavity corresponding in negative form to outside and inside dimensions of the atomizer nozzle and being filled with liquid or thixotropic production material thereafter made to solidify, the mould having a flow chamber core mould part defining the flow chamber inner wall and a mouthpiece core mould part defining the mouthpiece chamber inner wall at least in a region of a transition between the mouthpiece chamber and the flow chamber, the flow chamber core mould part having an outer surface with a substantially smooth and continuous contour in the region of the transition between the flow chamber and the mouthpiece chamber, the outer surface defining the flow chamber inner wall, the mouthpiece core mould part having an edge encircling the outer surface of the flow chamber core mould part and being disposed in sealing contact against the substantially smooth and continuous contour of the outer surface of the flow chamber core mould part at the transition between the flow chamber and the mouthpiece chamber, the edge of the mouthpiece core mould part forming an intersection of an outer surface of the mouthpiece core mould part and an inner surface of the mouthpiece core mould part facing away from the outer surface thereof, the outer surface of the mouthpiece core mould part defining the mouthpiece chamber inner wall from the intersection to an outlet edge of the mouthpiece chamber from which liquid emerges, and the outer and inner surfaces of the mouthpiece core mould part together define an angle of less than 90 degrees at the edge.

15. A mold for forming an atomizer nozzle, said mold comprising an outer mold having an inner wall surface defining a cavity corresponding in negative form to outer dimensions of a finished atomizer nozzle, a mouthpiece core mold part and a flow chamber core mold part each disposed within said cavity of said outer mold and each having an outer wall surface opposed to and spaced inwardly from said inner wall surface of said outer mold, said outer wall surfaces together corresponding in negative form to inner dimensions of the finished atomizer nozzle, said mouthpiece core mold part defining a central axis corresponding to a direction along which liquid emerges from the finished atomizer nozzle, said mouthpiece core mold part having an annular edge portion and said outer wall surface of said flow chamber core mold part having an annular area, said annular edge portion of said mouthpiece core mold part being disposed in surrounding relation with said annular area of said outer wall surface of said flow chamber core mold part, part of said annular edge portion being disposed in contacting and sealing relation with part of said annular area to define an annular parting line between said mouthpiece core mold part and said flow chamber core mold part, said part of said annular edge portion being a radially outermost part of said outer wall surface of said mouthpiece core mold part at said annular parting line and said part of said annular area being a radially outermost part of said outer wall surface of said flow chamber core mold part at said annular parting line such that each of said parts are disposed to contact atomizer nozzle production material located between said outer wall surfaces and said inner wall surface of said outer mold, said annular area of said flow chamber core mold part having a smooth and continuous contour.

16. The mold according to claim 15, wherein said smooth and continuous contour is without offsets, edges or grooves, and extends beyond said annular parting line.

17. The mold according to claim 15, wherein said part of said annular edge portion of said mouthpiece core mold part defines a terminal annular edge of said annular edge portion, said terminal annular edge and said part of said annular area of said outer surface of said flow chamber core mold part each have a diameter defined at said annular parting line, the diameter of said terminal annular edge being greater than the diameter of said part of said annular area.

18. The mold according to claim 15, wherein said mouthpiece core mold part has an inner wall surface facing away from said outer wall surface thereof, said inner wall surface of said mouthpiece core mold part defining a recess which opens upwardly toward said flow chamber core mold part, said flow chamber core mold part having an end portion on which said annular area is disposed, said annular area of said end portion having a frustoconical configuration with said smooth and continuous contour extending beyond said annular parting line.

19. The mold according to claim 18, wherein said part of said annular edge portion of said mouthpiece core mold part is a terminal annular edge and defines an intersection between said inner wall surface of said mouthpiece core mold part and said outer wall surface thereof, and said inner wall surface of said mouthpiece core mold part and said outer wall surface thereof together define an angle of less than 90 degrees at said terminal annular edge.

20. The mold according to claim 18, wherein said recess is frustoconical in configuration.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a partially sectioned view of a mould according to the invention for producing an atomizer nozzle,

(2) FIG. 2 shows an enlarged illustration of the detail B in FIG. 1,

(3) FIG. 3 shows a side view of a flow chamber core mould part and of a mouthpiece core mould part of the mould in FIG. 1,

(4) FIG. 4 shows a partially sectioned front view of the flow chamber core mould part and of the mouthpiece core mould part in FIG. 3,

(5) FIG. 5 shows a side view of an atomizer nozzle having a flow chamber core mould part and a mouthpiece core mould part,

(6) FIG. 6 shows a front view of the arrangement in FIG. 5,

(7) FIG. 7 shows a view of section plane C-C in FIG. 6,

(8) FIG. 8 shows an arrangement corresponding to FIG. 5,

(9) FIG. 9 shows an arrangement corresponding to FIG. 6,

(10) FIG. 10 shows a view of section plane D-D in FIG. 9, wherein two different mouthpiece core mould parts are depicted in this sectioned view for the sake of clarity,

(11) FIG. 11 shows an atomizer nozzle having a flow chamber core mould part and a mouthpiece core mould part in accordance with another embodiment of the invention,

(12) FIG. 12 shows a front view of the arrangement in FIG. 11,

(13) FIG. 13 shows a view of section plane E-E in FIG. 12,

(14) FIG. 14 shows a partial side view of a flow chamber core mould part and of a mouthpiece core mould part in accordance with another embodiment of the invention in the assembled state, and

(15) FIG. 15 shows an enlarged illustration of the detail XV in FIG. 14 in the partially sectioned state.

DETAILED DESCRIPTION

(16) The illustration in FIG. 1 shows a mould 10 according to the invention for producing an atomizer nozzle 12. The outlines of atomizer nozzles 12, 14 produced using the mould 10 are most easily seen in the sectioned views in FIG. 7 and FIG. 13. FIG. 7 shows an atomizer nozzle 12 in section, and FIG. 13 shows an atomizer nozzle 14 in section. Atomizer nozzle 12 can also be seen in part in the illustration in FIG. 5 and FIG. 6, and atomizer nozzle 14 can be seen in part in FIG. 11 and FIG. 12. The atomizer nozzles 12, 14 each have an inlet chamber region 16 and a flow chamber region 18 as well as a mouthpiece region 20 or 22. The characteristics of the atomizer nozzles 12, 14 are determined by the configuration of the respective inner wall thereof, i.e. an inlet wall 24 within the inlet region 16, a flow chamber wall 26 within the flow region 18, a mouthpiece wall 28 within the mouthpiece region 20 and a mouthpiece wall 30 within the mouthpiece region 22. Here, the wall 24 of the inlet region 16 and the wall 26 of the flow region 18 are defined by an outer wall 32a of a flow chamber core mould part 32. In the embodiment shown in FIG. 7, the wall 28 of mouthpiece region 20 is defined by an outer wall 34a of a mouthpiece core mould part 34, and in the embodiment of FIG. 13 the wall 30 of mouthpiece region 22 is defined by an outer wall 36a of a different mouthpiece core mould part 36. A comparison of FIGS. 7 and 13 will show that the atomizer nozzles 12, 14 each have identical inlet walls 24 and identical flow chamber walls 26, but differ in the configuration of their respective mouthpiece walls 28 and 30. More specifically, the mouthpiece wall 28 of atomizer nozzle 12 has a larger inside diameter than the mouthpiece wall 30 of atomizer nozzle 14.

(17) In FIG. 1, atomizer nozzle 12 is shown partially in section within the mould 10. The mould 10 has an outer mould 40, which in negative form defines the outside dimensions of atomizer nozzle 12. Inserted into the outer mould 40 are the flow chamber core mould part 32 and the mouthpiece core mould part 34 which, in turn, define in negative form the inside dimensions of atomizer nozzle 12, cf. FIG. 7. An interspace between the outer mould 40 and the flow chamber core mould part 32 and mouthpiece core mould part 34 is filled with a liquid or thixotropic production material, e.g. a ceramic material, to produce an atomizer nozzle. The production material is then made to solidify. After the removal of the outer mould 40, which has multiple parts, for example, the mouthpiece core mould part 34 can then be removed. The flow chamber core mould part 32 is designed as a lost mould and is burned out, for example, if appropriate during the firing of the production material.

(18) The mould 10 according to the invention is characterized in that the flow chamber core mould part 32 has a substantially smooth surface and continuous contours in the region of the transition 42 between the flow chamber wall and the mouthpiece wall. In the embodiment illustrated, the surface of the flow chamber core mould part 32 is of conical design in the region of the transition 42. The mouthpiece core mould part 34 is placed against the flow chamber core mould part 32 in the region of the transition 42. As can be seen in FIG. 1, the mouthpiece core mould part 34 is placed against the flow chamber core mould part 32 in such a way that an encircling edge 44 of the mouthpiece core mould part 34 rests in a sealing manner against the surface of the flow chamber core mould part 32 and thereby defines an edge at the transition 42 between the flow chamber wall 26 and the mouthpiece wall 28, 30.

(19) FIG. 2 shows the detail B in FIG. 1 on an enlarged scale. More specifically, FIG. 2 shows that the encircling edge 44 of the mouthpiece core mould part 34 is formed by the intersection of an outer surface 46 of the mouthpiece core mould part 34 and a bearing surface 48 of the mouthpiece core mould part 34. The bearing surface 48 is of encircling design and of frustoconical design and defines a recess 48a of the mouthpiece core mould part 34 which opens towards the flow chamber core mould part 32 and into which an end portion 32 of the flow chamber core mould part 32 projects. The bearing surface 48 is formed parallel to the frustoconical surface of the flow chamber core mould part 32 at the transition 42. As a result, the bearing surface 48 rests flat against the surface of the flow chamber core mould part 32 and, in particular, there is no interspace between the encircling edge 44 and the surface of the flow chamber core mould part 32. As a result, the production material cannot pass between the mouthpiece core mould part 34 and the flow chamber core mould part 32 as the mould is filled with liquid or thixotropic production material. As a result, the atomizer nozzle 12 has a precisely defined geometry and, specifically, a defined, sharp encircling edge in the region of the transition 42.

(20) The mouthpiece core mould part 34 can be preloaded in the direction of the flow chamber core mould part 32 in order to ensure that the bearing surface 48 and the edge 44 rest against the flow chamber core mould part 32 in a sealing manner over the entire circumference. It is even possible here to make provision for the bearing surface 48 and the edge 44 to press into the flow chamber core mould part 32 by a certain amount, although this is not shown in FIG. 2. It is thereby possible to compensate for tolerances in the production of the flow chamber core mould part 32 and of the mouthpiece core mould part 34. It is expedient here if the mouthpiece core mould part 34 is composed of a harder material than the flow chamber core mould part 32. The damage to the flow chamber core mould part 32 due to the pressing in of the encircling edge 44 and of the bearing surface 48 is of no significance here since the flow chamber core mould part 32 is in any case conceived as a lost mould.

(21) From FIG. 2 it can furthermore be seen that, when viewed inwards from the bearing surface in the circumferential direction, a cavity 50 is provided between the flow chamber core mould part 32 and the mouthpiece core mould part 34, said cavity being formed by an undercut on the mouthpiece core mould part 34 radially on the inside of the bearing surface 48. This undercut or the cavity 50 ensures that the mouthpiece core mould part 34 rests on the flow chamber core mould part 32 only by means of the bearing surface 48 in the region of its outer circumference. As a result, reliable sealing of the mouthpiece core mould part 34 and the flow chamber core mould part 32 can be ensured.

(22) The illustration in FIG. 3 shows a side view of the mouthpiece core mould part 34 and of the flow chamber core mould part 32 in the disassembled state.

(23) FIG. 4 shows a view of section plane A-A in FIG. 3. The mouthpiece core mould part 34 defines the inner wall 28 of the mouthpiece region 20 between the encircling edge 44 and an outlet edge 52 and thus defines that region of the inner wall 28 of the mouthpiece region 20 which is important for the flow profile within the atomizer nozzle 12. The encircling bearing surface 48 and the undercut 49 provided below the bearing surface 48 in FIG. 2 can furthermore be seen in FIG. 4. The undercut 49 is achieved by selecting a steeper angle of taper for the undercut 49 than for the bearing surface 48. An angle between a central longitudinal axis of the mouthpiece core mould part 34 and the bearing surface 48 is thus greater than an angle between the central longitudinal axis and the undercut 49.

(24) The mouthpiece core mould part 34 is of rotationally symmetrical design and has a concentrically arranged stud 54, which is of frustoconical design and matches a frustoconical recess 56 in the flow chamber core mould part 32. As the mouthpiece core mould part 34 is inserted into the recess 56, the mouthpiece core mould part 34 and the flow chamber core mould part 32 are thereby automatically aligned correctly with respect to one another. The stud 54 of the mouthpiece core mould part 34 is inserted into the recess 56 until the encircling edge 44 and the bearing surface 48 are resting on the conical surface 58 of the flow chamber core mould part 32.

(25) The stud 54 is provided with a central hole 60 which passes through the entire mouthpiece core mould part 34. A screw can be inserted into the central hole 60, and then penetrates the central hole 60 and is screwed into the material of the flow chamber core mould part 32. In this way, a defined preload between the mouthpiece core mould part 34 and the flow chamber core mould part 32 can be set and maintained.

(26) The particular advantage of the invention will be seen from a comparison of FIGS. 7, 10 and 13.

(27) FIG. 7 shows mouthpiece core mould part 34, which is placed against the flow chamber core mould part 32, thereby defining an inner wall of atomizer nozzle 12 with the mouthpiece wall 28.

(28) FIG. 13 shows mouthpiece core mould part 36, which is placed against the flow chamber core mould part 32, thereby defining an inner wall of atomizer nozzle 14 with the mouthpiece wall 30.

(29) In FIG. 10, a further mouthpiece core mould part 34 and the mouthpiece core mould part 36 are placed one above the other in order to illustrate that both mouthpiece core mould part 36 and mouthpiece core mould part 34 can be placed against the flow chamber core mould part 32 in a sealing manner and that mouthpiece core mould part 36 has a significantly smaller diameter than mouthpiece core mould part 34 at the end thereof which is placed against the flow chamber core mould part 32. Here, the substantially smooth contour with a continuous contour profile of the flow chamber core mould part 32, said contour being visible in the cross-sectional views in FIGS. 1, 4, 7, 10 and 14, makes it possible to place each of the different mouthpiece core mould parts 34 and 36 against the surface 58 in a sealing manner. This is because mouthpiece core mould part 36, like mouthpiece core mould part 34, is provided at the end thereof which rests against the surface 58 with an encircling edge 64 and a bearing surface adjoining the encircling edge 64 radially on the inside, the bearing surface likewise being of frustoconical design. Mouthpiece core mould part 36 furthermore has a central stud 54 of identical design to that of mouthpiece core mould part 34, thus allowing it to be centred on the flow chamber core mould part 32 in the same way as mouthpiece core mould part 34.

(30) The substantially smooth surface 58 of flow chamber mould part 32 in the region of the transition 42 between the flow chamber wall 26 and the mouthpiece wall 28 therefore makes it possible to use identical flow chamber core mould parts 32 together with different mouthpiece core mould parts 34, 34, 36 in order thereby to produce atomizer nozzles 12, 14 with different mouthpiece diameters. It can be seen that the surface 58 does not have any edges or grooves, and it can also be seen that the contour of the surface 58 does not have any offsets, edges or grooves. The outer mould 40 in FIG. 1, the flow chamber core mould part 32 and the mouthpiece core mould parts 34, 34, 36 form a mould set for the production of different atomizer nozzles.

(31) As explained, the flow chamber core mould part 32 is conceived as a lost mould, and therefore a flow chamber core mould part 32 has to be produced for the production of each atomizer nozzle 12, 14. The negative moulds for producing the flow chamber core mould parts 32, which are composed of polystyrene for example, are very expensive. Using identical flow chamber core mould parts 32 to produce different atomizer nozzles 12, 14 therefore considerably reduces the costs for producing the moulds 10 and hence also the costs for producing the different atomizer nozzles 12, 14.

(32) The illustration in FIG. 14 shows in part a mouthpiece core mould part 60 and a flow chamber core mould part 32 in the state in which one is placed against the other. The flow chamber core mould part 32 is identical to the flow chamber core mould part already described and will therefore not be described again. The flow chamber core mould part 32 is composed of a foam-type material, e.g. polystyrene or rigid foam.

(33) The mouthpiece core mould part 60 is placed against the flow chamber core mould part 32 and is sealed off with respect to the flow chamber core mould part 32 in the region of an edge 62, ensuring that no material can penetrate between the mouthpiece core mould part 60 and the flow chamber core mould part 32 and thereby forming unwanted flash as the mould is filled.

(34) FIG. 15 shows the detail XV in FIG. 14 in the partially sectioned state on an enlarged scale. It can be seen that the mouthpiece core mould part 60 has an encircling nose 64 on its upper rim, that facing the flow chamber core mould part 32, said nose extending in the direction of the flow chamber core mould part 32. In the state illustrated in FIG. 15, this encircling nose 64 has already penetrated by a certain amount into the material of the flow chamber core mould part 32 and thereby ensures that the edge 62 is sealed off and thus that a sharp but flash-free edge forms on the finished nozzle.

(35) The mouthpiece core mould part 60 is composed of a rubber material, for example, wherein the region of the nose 64 is formed by means of a reinforcing ring, which is mounted on the rest of the mouthpiece core mould part 60. The reinforcing ring can be composed of a somewhat harder material than the mouthpiece core mould part 60 in order, on the one hand, to ensure that it presses into the flow chamber core mould part 32 and, on the other hand, to ensure multiple uses.